一种复合式非线性低频隔振器的隔振特性分析

Analysis of vibration isolation characteristics of a compound nonlinear low frequency vibration isolator

抑制舰船动力设备的低频振动是一个热点问题。利用斜置式惯容结构获得非线性特性,并将其与经典ISD(inerter-spring-damper)隔振器相结合,构造一种复合式非线性低频隔振(CNI)系统。基于谐波平衡法对谐波激励下隔振系统的稳态响应及力传递率进行分析,研究惯质比和弹簧刚度对于隔振效果的影响,并与经典ISD隔振器及经典QZS(quasi-zero stiffness)隔振器进行对比。结果表明,该复合式非线性低频隔振器拥有更宽的隔振频带及更优的力传递性,这些发现能够为舰船低频隔振器的设计提供新的思路。

Suppression of the low-frequency vibration of ship power equipments has become one of the major concerns. The nonlinear characteristics of inverters were obtained by using an inclined inerter structure. A composite nonlinear low frequency vibration isolation system was constructed by combining the inerter structure with the classic ISD(inerter-spring-damper) vibration isolator. The steady-state frequency response relationship and force transmission rate of the system were obtained by using the harmonic balance method. Influence of the inertia-mass ratio and spring stiffness on the vibration isolation system was analyzed. Comparison with the classic ISD and the QZS(quasi-zero stiffness) vibration isolator shows that the composite nonlinear low frequency vibration isolation system has a wider frequency band and a better force transmissibility.These findings provide new ideas for the design of low-frequency vibration isolators.